Acohort study of red tide exposure and asthma compared exposed beach dwellers with non-exposed residents of the same community over a 30 year period. researchers found that the incidence of asthma among exposed residents was 73.5 per 1000. the incidence of asthma in non-exposed residents was 22.8 per 1000. calculate the relative risk and attributable risk of exposure to red tide and the development of asthma.